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yum Archives ⋆ SysAdminStuff

Yum and curl returning “Illegal instruction (core dumped)” on Xen

When running yum or curl commands on a CentOS 6 XenServer Virtual Machine you might be getting an “Illegal instruction (core dumped)” error returned in your console output.

root@server [~]# yum update
Loaded plugins: fastestmirror, rhnplugin
Setting up Update Process
Loading mirror speeds from cached hostfile
 * base:
 * cloudlinux-x86_64-server-6:
 * extras:
 * updates:
Illegal instruction (core dumped)

The issue is due to Python attempting to execute a CPU opcode advertised as available by the server’s host node virtualization system (XEN), but is not actually supported by the host node’s hardware.


Issue can be resolved by running export NSS_DISABLE_HW_AES=1, and then running yum update, to update to newer packages, after which issue should not be happening anymore.

root@server [~]# export NSS_DISABLE_HW_AES=1
root@server [~]# yum -y update

systemd conflicts with initscripts during yum update

When running yum update on CentOS 7 OpenVZ container you might get a following error:

--> Processing Conflict: systemd-219-19.el7.x86_64 conflicts initscripts < 9.49.28-1 
--> Finished Dependency Resolution
Error: systemd conflicts with initscripts-9.49.17-1.el7.x86_64
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Exact version I was running on this server is CentOS Linux release 7.1.1503 (Core), and updates were failing due to them requiring a newer systemd version, which required a newer version, v9.49.28 at least,  of initscripts installed.

Reason why systemd was conflicting with current version of initscripts, instead of just updating them to newer version, was that initscripts were excluded from update in yum.conf file.

[root@server ~]# grep exclude /etc/yum.conf

There are no default exclude packages in default CentOS/RHEL installs, and it wasn’t put there by me, so question is why was initscripts excluded from updates.

Issues with initscripts v9.49.24 in CentOS 7 OpenVZ containers

It turns out there were some issues with initscripts v9.49.24, which seemed to introduce problems with network connectivity on CentOS 7 OpenVZ VPS machines.

I commented out exclude=initscripts* from yum.conf, and checked the currently available version.

[root@server ~]# grep exclude /etc/yum.conf
[root@server ~]# yum check-updates initscripts
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base:
 * epel:
 * extras:
 * updates:
 * webtatic:

initscripts.x86_64                                               9.49.30-1.el7                                                base

Current version is v9.49.30, so I presumed issues with v9.49.24 were corrected in this version, and proceeded with the update.

Update has completed successfully, and all packages including initscrips were updated to latest version, as was CentOS.

[root@server ~]# cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)

I haven’t noticed any network or any other issues on the VPS after the upgrade, so it seems any network issues from v9.49.24, don’t exist in v9.49.30.

[root@server ~]# rpm -qa | grep initscripts